Thanks tally. Maybe a build thread someday but im really just trying to get this thing running right. Still hoping maybe somebody out there will see this and throw some knowledge my way.
Still working on cleaning the injectors but there hasn't been any signs of excessive gunk so far. 1 of the insulators didn't set right and was kinda deformed but looked like it was still sealing and not obstructed, but other than that seemed all good.


I'll keep updating the thread with my progress. I'm not just sitting around waiting for somebody to fix it for me - I'm working on this thing every chance I get!

 

All within spec. Valve covers ready to go back on tonight.

 

Well theres $600 down the drain - at least my engine bay looks nice. New injectors, new knock sensors, and egr deleted - still runs the same.

 

I saw early on you said the ECU issues had been “….sorted out….” but what did you really mean? Unless you sent it out to have the capacitors replaced and a full trace diagnostic and testing completed then I would not trust that ECU. A lot of gremlins occur when the PC board traces are damaged by leaking capacitors and weird issues ensue.

Worth double checking IMO. I prefer SIA for this service since that is their main focus. I have not heard of the ECU rebuilder you used.

https://www.clublexus.com/forums/per...ml#post9257259

BTW, all the work you have done looks stellar and it must be frustrating not getting to the bottom of the issue.

 

Thanks for the reply. I have (2) ecus that both exhibit the same problem so after 1 of them was rebuilt and the problem remains I pretty much ruled out the ecu as the source. But im going to try a few more things and then send it back to him to recheck it just in case.

 

Maybe have your cats checked? Maybe 1 or both cats may be clogged? On the ECU subject, I'd have 1 ECU sent back to be rechecked and in your case I'd send the 2nd one to another place for a 2nd opinion incase there is an overlooked problem that needs to be corrected.

 

Thanks again for the reply. The cats have been deleted - that was the first thing I expected as the loss of power seemed to correlate with the exhaust (stock) getting much quieter. When it ran good it had a nice exhaust note around 3500 and up but that was gone with the loss of power.

The muffler shop did I ****ty job and only introduced more leaks but those have been patched as far as i can tell. There was no change in performance if anything it feels worse than it did before they were removed but probably only because I can hear it better - makes a kinda sputtering sound so there may still be some leaks to address. I have since removed the rear o2s and ran the car with the holes open to rule out any exhaust restrictions. It felt the same from what I could tell. My next step is replacing the crank sensor even tho it tests fine - should be here tomorrow.

On the ecu thing I'm not completely ruling it out but I'm reluctant to pay to have a second ecu rebuilt since it seems like a long shot that both ecus would have the same issue even after 1 has been rebuilt.... I might be able to borrow an ecu from a friend to try tho.

 

Crank sensor finally came in today but I'll be surprised if that changes anything. I think it's actually the fuel pump even tho it tested good for flow and fuel pressure. I was reading about symptoms of a failing pump today and alot of them lined up really well with my issues so I'm gonna change that out next I think 🤔

 

Changed out the crank sensor and fuel pump and no change to the problem. At this point I'd say the fuel system has been completely ruled out.

 

Went thru the whole list of diagnostic checks on the ignition circuit and everything checks out.

 

I swapped in my other ecu and got the knock sensor codes immediately (no surprise). Then I swapped in the rebuilt ecu and I got the KS code again (surprise). Ive been running the rebuilt ecu for years now and never had a code from it. I think the only explanation is there is a problem with the wiring near the ecu connector and it got tweaked when I swapped ecus. I moved the wires around a bit and reset the code and now the code is gone and it's back to where it was before - no codes but still has the poor performance issue. I'll do some more checking on the wire harness and see if I can find a short somewhere but all the ecu wires look to be in excellent condition and I tested the wiring when I replaced the KS so it must be intermittent if at all...

 

Well I did a bunch of continuity tests on the ecu wiring and read the KS waveform thru the ecu connector and there didn't seem to be any wiring issues. Hooked it back up and now the KS code is back. It gets triggered pretty much immediately when driving but haven't seen it pop up at all at idle. I don't know how much more of this bs I'm up for...

 

I made my own knock sensor harness out of some coaxial TV wire and swapped it in. I tapped into the factory harness at the plug near the firewall. So far the knock sensor code is gone but no improvement to performance. I also deleted the fuel pressure vsv.